[Nuance]

Many answers from questions from the last two posts can be found in Floyd Toole's new book: "Sound Reproduction."  At least answers based on controlled listening sessions anyway; nothing is touted as a fact in that book, but it's a great read and I highly recommend it.  It covers reflections in great detail, and uses the listening tests to help explain why and how the brain and ears interpret things.

ratso,

I found the two articles you mentioned a few years back and they helped me as well (in a huge way).  That stuff is just priceless IMO!

[Saturn94]

Thanks for the link.  Off-axis performance is a very complex subject.  It matters for two reasons.  First, without complete toe-in, the first arrival sound will be off axis horizontally, although the angle won't be very large.  Second, most of the sound we hear is reflected, and the reflections will come from all of the sound that the speaker radiates into the room vertically and horizontally.  So if there is, say, a serious off-axis peak, you will hear that in the reflected sound field.  And if dispersion is very narrow in the highs relative to the mids and lows, you will also hear that.  But--how does the brain process all of these reflections that arrive at different times, reduced strengths, and with different frequency responses.  I don't know.  So it's difficult to predict just how important various departures from flatness will be in the off-axis response.  I mainly check for serious peaks in the horizontal off-axis response, which usually occur in the lower treble where the tweeter's response may be much more dispersed than the upper range of the woofer or mid.

So how well do the Salks (especially the HT2-TL) with the RAAL tweeter do in this regard (I've not seen any off axis measurements ).

[Saturn94]

yep it does (see below). BTW i have probably learned more about speakers, equalization, and audio in general in the last three days than i have in my whole life up til now when i came across this thread:

http://www.audiocircle.com/index.php?topic=58304.0

it's all good, some of it is pretty technical but the REAL gem as far as i am concerned is the two part article " Maximizing Loudspeaker Performance in Rooms - Why Loudspeakers Sound the Way They Do./Maximizing Loudspeaker Performance in Rooms Part 2 - The Acoustical Design of Home Theaters "

it explains why nulls in bass can't be corrected with equalization (only peaks can) and why equalizers should only try to fix the bottom couple hundred Hz of the FR (the krk only corrects up to 500Hz). hope this helps someone as much as it helped me. it also pointed out that a major factor in making good sounding speakers is having not only strong on-axis frequency response but also strong off-axis response (i thought that only mattered to the people sitting next to you from the 'sweet spot'). i mention this here because salks seem to have excellent off-axis measurements. it also shows that almost no one publishes measurements that are really useful to determining how a speaker will sound in your home (although someone that did it right was tom andry in the audioholics review of the salks).

i should also point out something interesting i came across in an old download of peter aczal's audio critic. in an interview with the designer from NHT ken kantor, he did experiments placing single audio sources in a circle around subjects heads and found that there is naturally in humans less cross-correlation at certain angles. and he found that that the angle that minimizes it the most is 21 degrees. so if you have your speakers at an equilateral triangle from you (30 degrees) a fun experiment is to move them closer together by 10 degrees and see if that WIDENS your soundstage some.

Thanks.  I'll check that out.

[ratso]

So how well do the Salks (especially the HT2-TL) with the RAAL tweeter do in this regard (I've not seen any off axis measurements ).

read the excellent review (with great measurements) at audioholics.

[Saturn94]

read the excellent review (with great measurements) at audioholics.

Thanks.  I did see that.

It would be interesting to see updated off axis measurents (and at wider angles than 30 degrees) with the new RAAL tweeter that is now used in the HT2-TL.

In one of the responses to that review there was a comment about the LCY tweeter's excellent disbursion being due to its height and width being about the same.  The RAAL tweeter on the other hand is a bit taller than it is wide.  Does this mean that the RAAL's vertical disbursion will be more limited?  Does this matter?  Does vertical disbursion affect perceived soundstage height?

[DMurphy]

Thanks.  I did see that.

It would be interesting to see updated off axis measurents (and at wider angles than 30 degrees) with the new RAAL tweeter that is now used in the HT2-TL.

In one of the responses to that review there was a comment about the LCY tweeter's excellent disbursion being due to its height and width being about the same.  The RAAL tweeter on the other hand is a bit taller than it is wide.  Does this mean that the RAAL's vertical disbursion will be more limited?  Does this matter?  Does vertical disbursion affect perceived soundstage height?

Well, when you come back to the Wehawken Rd Studios, we can measure a speaker with the RAAL and see how it compares.  But the answer is that its horizontal dispersion is somewhere between the G2 (widest) and the LCY (least wide).  That's a function of the width of the ribbon element.  The vertical dispersion should be about equal to the G2, and a little less than the LCY.  The conventional wisdom is that horizontal is more important than vertical, assuming the latter is reasonably wide, and very wide vertical dispersion is not necessarily a good thing since you get more ceiling reflections.  The RAAL speakers certainly aren't deficient in imaging height.

[Saturn94]

Well, when you come back to the Wehawken Rd Studios, we can measure a speaker with the RAAL and see how it compares.  But the answer is that its horizontal dispersion is somewhere between the G2 (widest) and the LCY (least wide).  That's a function of the width of the ribbon element.  The vertical dispersion should be about equal to the G2, and a little less than the LCY.  The conventional wisdom is that horizontal is more important than vertical, assuming the latter is reasonably wide, and very wide vertical dispersion is not necessarily a good thing since you get more ceiling reflections.  The RAAL speakers certainly aren't deficient in imaging height.

Thanks Dennis.  I look forward to returning.

So bottom line, horizontal tweeter disbursion has improved in the HT2-TL with the new RAAL tweeter, right?

[Saturn94]

yep it does (see below).

i should also point out something interesting i came across in an old download of peter aczal's audio critic. in an interview with the designer from NHT ken kantor, he did experiments placing single audio sources in a circle around subjects heads and found that there is naturally in humans less cross-correlation at certain angles. and he found that that the angle that minimizes it the most is 21 degrees. so if you have your speakers at an equilateral triangle from you (30 degrees) a fun experiment is to move them closer together by 10 degrees and see if that WIDENS your soundstage some.

Some time ago I did a bit of placement experimention and settled on a spot that seem to present the best imaging and soundstage width/depth. Today I did quick calculation (using a triangle side/angle calculator I found online ) which revealed an angle of 23.3 degrees.  Interesting how close it is to the 21 degrees you quoted.  I did try positioning them to achieve 21 degrees, but it put them right up to the sides of my 60" plasma and too close to the wall behind.  This caused some degradation of imaging and depth of soundstage.  I should note that because of my room setup (among other things, my seating and TV positions are fixed), I lack a bit of flexibility in speaker placement.

Out of curiousity, I placed the speakers a bit farther apart (about 30 degrees out) with some interesting results.  Overall width of soundstage didn't seem that much different overall (it was still very wide), but imaging off to the sides of the speakers was better with the speakers closer together!  I would have expected that bringing the speakers closer together would have narrowed the soundstage.  I didn't expect that with the speakers closer together that a wide soundstage could be maintained with better imaging within that soundstage.

It would be interesting to hear from someone who has more placement flexibility to see what they think trying out the 21 degree position.

(I know this is getting off the original topic........my appologies to those coming here to read comparisons between the HT2-TL and the HT3)

[vintagebob]

(I know this is getting off the original topic........my appologies to those coming here to read comparisons between the HT2-TL and the HT3)

This thread may help and would be a great thread to post setup questions in?

http://www.audiocircle.com/index.php?topic=78833.0

[Saturn94]

This thread may help and would be a great thread to post setup questions in?

http://www.audiocircle.com/index.php?topic=78833.0

Thanks for the great link.